Whether you want to swap out your doorknob for a newer style or repair an existing one, knowing the different parts of the doorknob and its lock helps you know what you need to buy. Doorknobs are made up of several different components.
Doorknobs have two handles, one on each side of the door, and are either locking or non-locking. A locking doorknob features a locking mechanism on the interior handle and a slot for a key on the exterior. On non-locking doorknobs, the interior and exterior handles are smooth and contain no locking mechanism.
The hardware of the doorknob includes screws and other metal pieces that help hold the doorknob on the door. Hardware varies by manufacturer and style.
The bolting mechanism is the metal piece that extends from the center of the doorknob into the door frame's latch hole to keep the door closed. The bolting mechanism has a spindle that retracts from the door frame when one of the handles is twisted, allowing the door to open.
An additional dead-bolt mechanism is typically installed in doors leading outside the home to provide extra security. It requires a key to retract the bolting mechanism from the door frame.
On doorknobs that have a lock, it is employed by a small lever or push button on the interior handle. The lock prevents the spindle of the bolting mechanism from retracting from the door frame, making it impossible to open the door. A key is required to open the door from the exterior side of the door.
The strike plate is a thin piece of metal installed into the door frame to reinforce the wood around the latch hole. Strike plates prevent the wood from wearing out and allow the door to latch and lock correctly.